1. Field of the Invention
The present invention in general relates to vehicle cargo bed covers and more particularly to a lock and roll up method.
2. Background and Related Art
Tonneau covers have been used for a number of years and used to cover the cargo box of pickup trucks and protect its interior against dirt, debris and other environmental contaminants and in some cases to improve the aesthetic quality thereof. Originally tonneau covers were designed by upholstery shops and typically made of vinyl covered fabrics or canvas. The material was often doubled over along its edges for added strength and appearance. Male snaps were then attached to the sides of the cargo box via fasteners, while female snaps were attached along the edges of the cover. Wooden bows were sometimes used to span the cargo box and ensure that the cover remained high enough to drain water. Unfortunately these covers were sometimes difficult to handle, often led to corrosion around the snaps and occasionally failed to protect the cargo box.
Over the years a wide variety of cover designs have been developed, in general these covers are known as either “caps” or “tonneau covers.” Caps are typically an enclosure that extends substantially above the bed so as to increase the height of the cargo bed while a tonneau cover typically lies substantially flush with the top walls of the cargo bed without significantly increasing the height of the cargo bed.
Most tonneau cover systems today are constructed of a solid or fabric material and employ an internal support frame work which installs to the cargo bed as a one piece system. Occasionally these systems can be hinged to provide an opening section thus providing access to the cargo bed or to stowed cargo. Clamp methods are often employed to allow alignment and installation of the cover system to the cargo bed or when on occasions it may be necessary to carry a load that exceeds the height limitations of the cover system, these clamps allow quick and easy removal from the cargo bed.
Many of these previous features were also incorporated in later designs with slight modifications. For example, U.S. Pat. No. 5,076,338, similar to U.S. Pat. No. 4,036,521 employed a pivoting rail to retain tightness of the tonneau cover material. In this particular system, an “L” shaped rail, which presumably puts the pivot lower for added mechanical advantage was used to tighten the tonneau cover material from a fore and aft position rather than cross-car position. This system further employed 45 degree angled frame rails and hook and loop system, known commercially under the trademark, VELCRO, as the fastener.
Relatively recently, a tonneau cover system having a screw adjustment mechanism was developed for permitting the fore and aft adjustment of the front rail. This screw adjustment mechanism serves to tighten the tonneau cover material in response to wear and to stretch that is common in tonneau cover systems. The tonneau cover system further employed the “L” shaped lever and lower-positioned pivot which requires the lever to carry an enormous amount of force. Consequently a stronger latch is required to overcome these loading forces and minimize wear and breakage. Frame rails coupled to the sidewalls of the cargo box using a plurality of clamps can be seen in U.S. Pat. No. 5,906,407 issued to Schmeichels. This disclosure of which is hereby incorporated and made a part of this application by reference.
A TRUXEDO cover which is not believed to be patented made by SHURCO includes a rotating, rectangular, rear rail having a rounded front pivot, vertical sides with VELCRO attachment and spring pins that push on a front rail mounted inboard of the side rails. These spring pins push against the front rail to tension the system in the fore-aft direction. The spring pins which are attached to the side rails via brackets may not firmly engage the front rail due to their inboard location which may cause the brackets to come out of alignment as the side rails rotate. Additionally the rounded shape of the front rails may cause the push pins to slip off-center. This disclosure of which is hereby incorporated and made part of this application by reference.
U.S. Pat. No. 6,293,608 issued to Dicke, discloses a tailgate rail interconnected to side rails with an interconnecting plate coupled to the side rails and slide able coupled to the corner piece for accommodating relative movement there between. A biasing device being a coil spring is further provided thus to provides tensioning to the tonneau fabric. This disclosure of which is hereby incorporated and made part of this application by reference.
U.S. Pat. No. 7,334,830 issued to Weldy, discloses a sectional tonneau cover having vertically suspended cam locks and having side to side adjustability provided for by slots in the frame. This disclosure of which is hereby incorporated and made part of this application by reference.